Construction of tank vessels.



1. w. ISHERWOOD & I. W. STEWART.

CONSTRUCTION OF TANK VESSELS.

APPLKIATIDN FILED MIG-17- 1 916. I

Patented Jan. 1, 1918.

' 9 SHEETSSNEET 2.

JQsep/r 14 lake/1100a an Jofin I44 SteWdrZZ 1y anon q J. W. ISHEHWOOD611. W. STEWART.

CONSTRUCTION OF TANK VESSELS.

APPLICATION FILED AUG-17,1916.

Patented Jan. 1, 1918.

9 s'nzlaIs-slusn 3.

J. w. lsuenwoon 41 W.-STEWART.

CONSTRUCTION OF TANK VESSELS.

APPLICATION FILED AUG-11. ISIS- 1 ,25 2,008. Patented Jan. 1, 191&

9 SHEETS -SHEET 4.

J. W. ISHERWOOD & J. W. STEWART.

CONSTRUCTION OF TANK VESSELS.

APPLICATION FILED AUG. 17. 1916.

Patented Jan. 1, 1918.

8 SHEETSSHEET 5- mm M N .Josep/z W. lslzerwooct M J0/m W Stewart, by

J. W. [SHERWOOD 61. l. W. STEWART.

CONSTRUCTION OF TANK VESSELS.

APPLICATION FILED AUGJT. 1916.

1,252,008. Patented Jan. 1, 1918.

9 SHEETS-SHEET 7- J. W. ISHERWOOD .& J. W. STEWART.

CONSTRUCTION OF TANK VESSELS.

APPLICATION FILED AUG-17. 1916.

Patented Jan. 1, 1918.

9.'SHEETSSHEET 9.

gnontozy Josep/v l/w; wood 41' J04): W. stcwa t, 6

UNITED STATES PATENT OFFICE.

JOSEPH WILLIAM ISHERWOOD AND JOHN WILLIAM STEWART, OF LONDON, ENGLAND.

, CONSTBUCTIQN O F TANK VESSELS.

. Specification of Letters Ifatent.

Patented Jan. 1, 1918.

To all whom it may concern: 1

Be it known that we, Josnrn WILLIAM Isnnnwoon and JOHN WJLLIAM' STEWART,both subjects of the King of Great Britain, residing at London, England,have invented certain new and useful Im rovements in Construction ofTank Vesse s; and we do hereby declare the followin clear, and exactdescription 0 the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

This invention relates to vessels especially adapted for carrying liquidcargoes, and has for its object to provide aconstruction which will beseaworthy in every respect, while at the same time requiring a lesstotal weight of "metal than has been heretofore necessary in bulk liquidcarrying vessels of the same kind and strength.-

With these and other objects in view the invention consists in the noveldetails of construction and combinations of parts more fully hereinafterdisclosed and particularly pointed out in the claims.

In order that the invention may be the more clearly understood it issaid :Tank vessels of this nature heretofore built, have been of thethree following classes ;-first, said vessels have. been provided withseveral transverse bulk-heads and a fore and aft middle line bulk-head,the latter considerably increasing the longitudinal strength;

second, said vessels have ,been provided with several transverse,- andtwo central fore and aft bulk-heads, the latter also givinincreasedlongitudinal stifl'ness; and, t ird, said vessels have beenprovided'with cylindrical tanks similar to cable tanks, which have beeneither ca able of removal from the vessel, or they ave been formedintoal with the structure of the. vessel.

In all three classes, and especially; in the third class of vessel, orthose heretofore built with cylindrical tanks, full advantage has notbeen taken of the opportunity to make thtanks themselves contribute tothe longitudinal strength-of the vessel.

Accordingly, the main object of the .pres-,v

ent invention is to so arrange the tanks, and to so distribute the metalin the vessel, that the ta ks themsel es will more materially to be afull,

. add to the longitudinal strength of the vessel, thereb morecfl'ectually saving in the total weig t of metal necessary to build aseaworthy ship. e

In addition to the above, the tanks in this invention are preferablymade of a boiler like construction, which reduces the labor as well asthe weight, and minimizes the necessary stiffening without in any wayinterfering with the strength requisite for seaworthiness' and for aproper classification. Stated in still other language, in vesselsconstructed in accordance with the present invention the tanks are of acircular, or approximately circular cross section, and they arepreferably arranged as a series of circles that overlap or encroach,npon each other when viewed in plan. In order to securely fasten thetanks together and thereby bring out their full strength for the purposeof longitudinally strengthening the vessel, a portion of the wall ofeach tank, as seen in plan, is omitted or cut away, so that a portion ofthe wall of one tank en? croaches on the interior of its adjacent tank vthereby permitting the two tanks to be ri 'dly attached to'each otheralong a plura ity of vertical lines transversely spaced apart. When theentire series of tanks are thus efiicientl attached to each other, thecollectively a d to the longitudinal strength of the vessel, or serve,the functions of longitudinal bulk heads, all as will presentalyappear.

The cutting away, or encroachment of the v tanksfl-on one anotherfurther enables the utilization to the utmostof the space in-the centralortion of the vessel, and therefore the tan sneed not be of aninconve'nient diameter. In'addition, this construction insures a'simplerand better attachment to the main structure of the vessel than is thecase with separate cylindrical tanks. Especially may the tank be themore easily attached to the shell and; deck platings and to the doublebottom plating, or to a se tin for the tanks, located at about the sameheight as the top plating, of the double'bottom, as will also presentlyappear.

The above construction of tank vessels, especially adapted for carryingliquids in ulk, can be applied either to o d vessels a1- ready built, orto newl designed vessels as may seem most desira le or convenient. at

the time.

Referring to the accompanying drawings forming a part of thisspecification in whlch like numerals designate like parts in all theviews Fig. 1 is a diagrammatic longitudinal sectional view taken on theline 11 of Fig. 2, showing a cargocarrying vessel converted into the newconstruction;

Fig. 2 is a diagrammatic sectional plan view of the vessel shown in Fig.1;

Fig. 3 is a transverse sectional view along the line 3-3 of Fig. lookingin thedirection of the arrows;

Fig.4 is a sectional view taken onthe line 44 of Fig. 5 looking in thedirection of the arrows; I

Fig. 5 is a sectional plan view taken on the line 5-5 of Fig.3;

Fig. 6 is an enlarged longitudinal sectional view of a'portion of thepart'sshown .in Fig. 5 and taken on the line 6-43 of said Fig. '7 is adiagrammatic sectional view partly in elevation 'of a newly designed vesselprovided with the construction forming the subject of thi invention;

Fig. 8 is a diagrammatic sectional plan view of a portion of the partsshown in.

ig. 9 is a transverse sectional view taken on the line 99 of Fig. 8;

Fig. 10 is an: enlarged detail view illustrating a bottom construction;

Fig. 11 is 'an enlarged detail view-taken on the line 11- 11 of Fig. 9;

Fi 12 is a cross sectional view taken on the l ne 1212 of Fig. 13; and

Fig. 13 is an enlarged sectional plan view taken on the line 13-13 ofFig. 12.

1 indicates the outer shell plating of the vessel, 2 the to plating, orinner bottom of said vessel, an 3 the space between the inner and outerplatings 1 and 2.

The space 3 may be divided oil by the longitudinalside walls or girders4 and by v the central longitudinal 'rders 5 as is usual Additionalvlongitudinals in such vessels. such as 100, 101, 102, and 103' may alsobe provided when'd'esired;

In the case of converting oldvessels to this construction, the vessel tobe converted may, for example, have one or more lower decks such as 6,see Fig. 3, andan upper deck such as 7 The lower deck or decks are cutaway wherever necessary to accommodate the vertical walls .8, of a tanksuch as 9 and which tanks are fitted in the vessel in the manner now tobe more fully described. The said tank 9, for example, convenientlyrests upon the top plating 2 or in single bottomed vessels, upon aseating provided for said tank 9, an said top the space 3 of the doublebottom a portion.

of the liquid carrying space of tank 9 as will be readily understood.

The sald wall 80f the liquid carrying tank 9 is conveniently secured tothe top plating 2 as by the circular angle bars or'other suitablesections 10, which may be securely riveted substantially all around tothe said wall 8 and to the said top 2 or other seating for the tank 9.The widely spaced deep.

Isherwood transverses are illustrated at 11, and the closely spacedshallow lon itudinals of the Isherwood system, are in icated at '12.Between the vertical wall 8 of the car 0 carrying tank 9 and the outershellv si e plating 13, is the longitudinal. space 14 which may beconveniently utilized for liquid or other cargo, as will likewisepresently appear.

Across the space 14 is the stiffening plate or member 15 rigidly securedto the Isherwood transverse "11 and to the vertical wall Softhe tank- 9as well as to the transverse beam or other stiffening member 16 as willbe clear from Fig. 3. Likewise across the away as indicated at 63 inorder to make I bottom of thespace 14 is a similar stiffening V member18 secured to the tank wall 8 near its bottom and to the Isherwoodtransverse 11 near the bil e of the vessel.

- The tank wa l 8 referably extendsup to the top deck 7, andis-efiiciently secured to the lon 'itudinal and transverse beams .ofsaid defii, so as to make the plating of deck 7 aid in bearing anystrains that may. be brought on said tank wall. On the exterior ofthetank and secured to the Isherwood transverse 20 is a plate orstiffening mem ber 21, in all respects similanto'the plate 15, whichplate 21 is likewise secured to the top portion of thewall' 8 and to thetransverse beam 22, so, as to further make the plating of deck 7 aid inbearing the strains of said side of thetank 9 is a-sti ening plate 23secured to the beam 22 and to the inside of tank wall. Opposite theElate 21 on the in v the wall 8 as will be clear from the drawings. Itwill thus be seen that the vertical wall 8 of thetank 9 is made anintegral 1 art of the, plating all around its circum erence,

so that any longitudinal strains brought on' said wallc'8' will bepartially borne by the bottom latin The c ircum likewise causes thestrains of the vertical wall 8 to be partially borne by said plating'6.

Itwill also be seen that the membersz2l,

15, 18,520 and 11 constitute what mi ht becalled a diaphragm or apartial bul shead erential angle fastening 104- in all respects similarto the fastening 10 cut away'to formthe longitudinal spaces 14 h and 25,adapted to receive liquid or other cargo. It will be'further seen below,that the other tanks is 'p 'ar ded with 40, 41'and 42 which are shown ascut away in order that the walls 0 the one aauaooa cured to the innersurface of thewall 8an d to-the top lating 2 or other seating for thetank as w-i 1 be clear from the drawings Referring now more particularlyto Fig. 2 the above-constructions are repeated for each tank of theseries of tanksx35, 36, 37, 38, 9, artially tank may enter into thewalls of an adjacent tank and be efficiently secured to each other aswill now be disclosed.

That is to say, the series of tanks thus set forth form acontinuouslongitudinal stiffening construction, which efiicientlyperforms the function of one or more longitudinal bulk-heads. Atransverse bulk-head at one end of the series is conveniently fittedacross the vessel asat 43 and at the other end of the series, anotherbulk-head 48 is likewise fitted across the vessel. In addition tothebulk-heads 43 and 48 partial bulk-heads are represented at 44, 45, 47,71, 72, 77 and the detail fastenings of which will be more fullydisclosed below.

As will be clear from Fig. 5, the tank 9 is cut away or a portionthereof omitted, as at 50, and an efiicient angle or other fasten ing 51is joined to the vertical cutaway walls of the said tank 9 and the outerwall 52 of, the tank 38 so as to form a liquid tight joint between thetanks 9 and 38.. Accordingly, any longitudinal strains which ma betransmitted to the tank 38 for examp e, will be further transmitted tothe tank 9. It frev quently becomes desirable to provide a space such as53 between a pair of tanks such as 38 and 9, to serve as a pump room,cofier dam or liquid space and in such case a curved partition wall 54is conveniently provided on the inside of the tank 38 and eflicientlyjoined to the walls of said tank as by the angle members 54 and 55.Inorder to stiffen the. partition wall 54 a plurality of hoop likemembers 56 suitably-spaced in a vertical direction, may be provided andin a order to stiffen the wall 52 ofthe tank38,

a similarly spaced hoop like member 57 may be provided. These said hooplike members may convenientlytake the form of curved angle bars as willbe clear from Fig. 6. v

The space 53 is thus segregatedirom the 'tanks 9 and 38, and if desired,an opening through that portion 59 of the wall of the tank 38 may be hadas indicated at 60, see

Fig. 6, thus affording communication be- I tween the space 7 0 outsidethe tanks and the se regated space 53. The top platin 2 is indicated inFig. 5, as provlded wlt the holes or orifices 63 above mentionedsothatliquid may readily pass from the inside of a tank such as 9 into thespace 3 of the double bottom, and similar holes indicated at 64,

'may be provided in that portionrof the top plating 2 underlying thetank 38. In order to prevent liquid from the tank 38 passing into thetank 9 through thespace 3 of the double bottom, it convenient to providecontinuous transverse floors '65 and 66 which extend liquid tightathwart ships fro m side to side and completely out 'ofi communicationfrom the one tank to the other.

The effect of thus providing liquid tight continuous floors, 65 and 66is to further cut off a space 67 in the double bottom between followsthat the space 53 may readily communicate with the space 70 through thedouble bottom when desired. The space 70 is conveniently formed by thepartial bulkheads 71 and 72 which are provlded with the angle fasteningsI 73 and 7 4 efliciently attaching said bulk-heads to the tanks 38 and 9respectively.

Said partial bulk-heads are conveniently attached to the top plating 2and to the longitudinal girder 4 as by the angle fastenings 105, seeFlg. 4.- Said partial bulk-heads are also conveniently stiffened as bythe vertically disposed angles 'or other stiifeners 106.

"said floors 65 and 66, which space is entered, by the holes 68 in the sace 53 and also entered by the holes 69 in the space 70. It

Horizontally disposed angles 107 'may be further providedy'and betweensaid an les there may be fitted the longitudinal sti ening members 01'plates 108 which eflectually resist any collapsing pressures that may beto the shell plating 13 ofthe vessel as shown and may constitutecontinuations of the widely spaced Isherwood transverses, or not,according to the particular construction emv ployed, all as will beclear to naval architect's. r i

By omittingfto cut away the partial bulkheads 71 anjd 72, the space 70as well as the space 53 may-:1 be kept dry or free from liquid,whilefltlieis laces such as 14 and 61 may be filled with when desired.The;

spaces 14 and 61 are conveniently cut off from the similar adjoiningspaces such as 76 as "by an unperforated partial bulk-head 77 joiningthe tank 40 and efiiciehtly attached thereto as by angle members such as78 The said tank 40 as indicated, in 1 ig. 5,,is

attached to the .wall portion of the tank 9 as by theeffieient anglefastenings 80 and in all cases tot-he top plating 2 by the completecircular angles 109. Likewise the tank 38 is secured to the top plating2 by the similar complete angle fastening 110, all as willbe'clearrto'nayal architects.

Should the opening 60 be omitted through Y closely analogous to therebeing no precisely the present construction have been given the the wallportion"59, of the tank 38, or should I both the spaces said openin beclosed liquidt-i course, liquid could-be carried in either or 53 and 70,as above intimated.

Of course, it will be understood that" the fastenings described inconnection with tanks 9 and 38, in so far as theyare applicable, are ormay be re eated in connection with every other pair 0 tanks. i

. Coming now to the somewhat modified form of the inventionillustrated'in Figs. 7

ght, then of to 11 inclusive, and which modification is especially it issaid :-Th,e construction here shown is that just described, but

same as will now appear But in so far as it is practicable thev artsthat are common to the preceding an the same reference characters.

Referring first to'Figs. 7 and.- s, in the newly designed vessel, themachinery 1Il-.

stead of being located near the center of the vessel, is located nearthe stern thereof, and accordingly, the series of tanks lettered 35, 36,37, 38, 380,40, 41 and 42 are joined together in one continuouss'eriesinstead of in two separate series. Further, the partialbulk-heads such as adapted for boats of new design decks to cut away itis not- 71 and 72 appearing in V Fig. 2, .have been transferred nearerthe stern of the vessel and now appear between the tanks 35, and 36,being lettered respectively 150 and 151.",

Another important difierence of the Iconstruction found in FigfS overthat found in Fig, 2 is the seating 152 for the tanks which seatingtakes the place, of the inner bottom or top plating 2 appearing in Figs.1 and 3 for example. In the newly designed boats this said 'seating152maybe only plating which stanchions are conveniently made of theconstruction shown in Fig. 11 and pass down through the tanks to the topplating 2 or tothe line ofthe seating 152 as illustrated. They areconveniently supported at the bottom by the-longitudinal member 5 andits associated transverse floors, as clearly shown in Fig. 9. p

'As appears in Fig.11, the said stanchions 175 are composed of theplates 178 provided attheir outer edges with the angles 179 and aresecured together as by the angles 180 and spaced part as sh n thestifieningplates 181 wh ich are vertically As will clearfrom Fig. 9there is locatedin'the longitudinal 183 betweenthe outer skin of thedinally' disposed diaphragm plates or menibers such as 1.84, 185, 186and 187 which are tank like spaces ship and the outer-walls of thetanks, the longituconveniently connected to the longitudinals 12, andwhich serveto stifien the construc- -tion in a. manner well understood.Said longitudinal members are crosse by the vertically disposed partial'bulk heads such as 188, 189,etc see Fig. 8, for example. a

Extending across the. tanks atsuitable intervals are the transversegirder like mem bers such as 190 which may be conveniently stifienedas-by the angles 191, and above said girders 190 f are the expansiontrunks 192 suitably sub-divided, and of the well known construction. I

The top plating 2 or seating 152 may be suitably stifi'ened whereverdesired as by the construction illustrated in Fig. 10, wherein 200represents a'longitudinalmember connected .to the transverse floorplates such as 159 by brackets such as 201 and 1202.

Referring now to Figs. 12 and 13 the construction in onesense, is acombination of the two preceding constructions in that it is applicableto newly designed boats,-but .is still provided with one or more in Fig.9.

Referring observed that the tank 35- is cut away and lower decks such as210. The other parts are or may be of spbstantially the sameconstruction as.

especially to Fig. 13, it will be i joined .tothe tank 36,-by the angle153,

while the hoops 154 and 155 corresponding tothe hoops 56'and 57 in Fig.5 are provided on'the walls 156 and 157 of said tanks respectively. Ittherefore follows that the partialirf all respects to the space 70 ofFig. 5. It will be observed that the-seating 152 I and therefore, itprevents liquid from passing into I bulk-heads 1 50 and 151 and the saidfloors 159 and 160 together with the seating 152 inclose aspace 164'which corresponds.

the. space 162 frorn the tank 35 inwthe manner preciselvsimilar to thetop plating 2 disclosed in eonnection with Fig. 5, and which in thatfigure prevents oil from pass ing' from the tank 9 intothe space 531 Itwill be consequentlvobserved that the com tinuous transverse floormember 160 in Fig. 13 in connection with the said seating 152.

located inside the tank 36 prevents the li'qiiid from passing s'oace-162and in the-same way the said continuous floors 159 and 160 inconnection with the .seating 152 preventsliq uid from pass 'ing fromboth thetanks 35 and 36 into the spaces164 and 183. all as will be clearfrom the descrintionof the like wns ruction illus- ,trebedinfEig. ,5.

from said tank 36 intof fihe 11clocated in the space 162 rests upon thetop sedge of the "continuous floor 159.

It will befurther understood that in the construction shown in Figs. 7to 13. it may be convenient to substantially duplicate atthe topportions of the tanks the construction of the seating 152, in order toefficiently secure the top portions of said tanks to the top or deckconstruction of the vessel, and a other cargo in the spaces such'as 14and 183,

located between the walls of the tanks and the sides of the vessel, itis desirable to connect these said side spaces with the interior of thetanks.

readily effected by means of the holes 230 in the longitudinal girder 4,and illustrated of said tanks. It will now be clear that this inventionenables the naval architect to utilize the metal of the tanks inobtaining the requisite longitudinal strength, and that therefore heneed 'not use as great a weight of metal in the ordinary class of vesselas usual. In other words, the naval architect can build a seaworthyvessel on this system with a total less'weight of metal thanhas Suchconnections may be Fig. 5. Of course, in such cases, in addition tions,the bulk-heads are or may tifiened wherever desired. I .It will now beclear that by omitting, or cutting away, a portion of the wall of eachtank and causing a portion of thewall of an adjacent tank to encroachupon, overlap, or enter the area that would have been occupied by saidfirst named tank had said portion of its wall not been omitted, and thenbindin the whole series of tanks together by rigid astenings at said cutaway portions, sald' series of tanks are caused to take on the nature oflongitudinal bulk-heads; and v further, when said series of connected.tanks are rigldly secured to the bottom, top, and side structures asdisclosed, they are enabled in addition to their functions ascontainers, to discharge" the functions of one or -more longitudinalbulk-heads in stiffening the vessel. e 1

In ot her words,' the tanks constitute holto the necessary faste'ningsor rigid connec der having. a vertical 'portlon of its wall disposededges as indicated at 50, Fig. 5,

low intersecting cylinders, a preceding cylinand a succeeding cylinderhaving a portion been heretofore thought possible in the ordinarytankers. r

.. It is obviousthat those skilled the art I v may vary the details'ofconstruction, as well as the arrangement of parts without depart ingfrom the spirit of the invention, .and therefore, it is not desiredto'be limited to the above disclosure except as may be required by theclaims.

What we claim is i 1. In a ship the combination of a pair of cylindricaltanks a portion of the walls of one of said tanks being omitted toprovide a tion of the walls of the other tank extending between saidedges to form a common and wall; fastening and stiffening connectionsbetween the meeting 'walls of said tanks; and additional fastening andstiffening connections between said tanks and the hull of the vesseladapted to cause said tanks to constitute a portion ofthe lon 'tudinal'stlflenlng of the ship, substantia ly as described.

2. In a ship the combination of a pair of tanks circular in crosssection, a portion of the walls of one of said tanks being omitted to'provide a pair of vertically disposed edges, and a portion of the wallsof the other tank extending between said edges to' form a common endwall; fastening and stiffening connections between the meeting walls ofsaid tanks; and additional fastening and stiffening connectionscomprising a partial transverse bulk-head and connectin members betweensaid tanks and the hul of the vessel adapted to cause said tanks toconstitute a portion of the longitudinal. stifl'ening of the ship,substantially as described. I 3. In a ship the combination of aplurality of tanks'located in a fore and aft line,

" a portion of the walls. of eachtank being omitted to providea pair ofvertically dis- .52 of its wall disposed between said edges,

and rigidly secured thereto. It thus results that the common end wall 52of an adjacent pair oftanks extends along the same pylln- A 6 dric'alcontour lines as the remaining walls posed edges; a portion of the wallof issueceeding tank extendin to form a common en wall; rigid "connections between adjacent tanks adapted to between said edges pair ofvertically disposed edges, and a porcause said tanks collectively toconstitute a.

portion of the longitudinal stiffening of the ship; connections at thebottoms of said tanks rigidly securing them to the bottom structure ofthe vessel connections at the top of said tanks rig idly, securing. themto the top structure .of-the vessel;and addi-- tional connectionscomprising a pluralityof partial bulk-heads rigidly securing said iaotanks to the sides of the vessel, substantially- I as described.

. cated between said edges to form a common end" wall; rigid connectionsbetween; said tanks at said omitted portions; rigid con nections betweenthe bottomedges of said 1 tanks and the bottom structure of thevescustomary in 7 described." A

f -5. In a ship rality of overlapping tanks circular in cross I .,se1;rigid connections between the top por- T tions ofsaid tanks and the topstructure of 15 the vessel; and rigid connections between vessel, saidtanks and connections constituta material portion of the longitudinalstrength of the vessel and the whole enabling the architect-to employ aless weight of metal in the ship than has been heretofore tank vessels,substantially as the combination; of a.pl u

qsection, apor'tlon of the walls of the one tank being omitted toprovide a pair of vertically disposed edges a portion of-the walls of anadjacent tank located between said edges to form a common end wall;rigid connections-between said tanks'at said omitted portions; rigidconnectionsbetweenthe bottom edges of said tanks andthe bottom tion ofthe walls of an adjacent structure of the vessel; rigid connections be.-tween the top portions of said tanks and the top structure of thevessel; rigid con-- nfictions between'the' sidesof said tanks and a t hsides of said vvessel; and connections 1 separating off a portion of thespace inside said tanks to form a pump room or other constituting amaterial portion of thelon tudinal'strength of thevessel-and there yenabling the architect to employ a less total weight of metal in theship' than has. been heretofore customary in tank vessels, substantiallyasdescribed. a A

6. In a sh p the combination of a. plu-- rality of overlapping tankscircular in cross section, a portion of the-walls of the one tank beingomitted to accommodate a por-" tank; rlgid connections between saidtanksat -said omitted portions; Ilgld connections between the bottomedges of said tanks and the bottom structure of the vessel; rigidconnections between the top portions of said tanksand the top structureof the vessel; rigid connections between the sides of said tanksand thesides of said vessel; and communicating means for connectin thespace-between the sides ofsaid tanks an the sides of the ship with theinterior of sa d tanks, or segregating said space from said interlor atwill; said tanks and connectionsconstituting. a material porbottoms andoverl omitted to accommodate a\ walls of an-ad acent tank; rigidconnections rigid 'tom having a top plating, the combination of aplurality of overlapping tanks circular i in cross section open at theirbottoms and a portion of the overlying [said plating, walls of the onetank being omitted to form vertically'disposed edges; a portion of thewalls of an adjacent tank located between said edges; rigid connectionsbetween said tanks at said omitted portions; rigid con-v the sides ofsaid tanks and the sides vof said 7 tanks and the bottom structure ofthe vessel; rigid connections between the top portions of said tanks andthe top structure of the vessel; and rigid connections between the sidesof said tanks and the sides-of said vessel; said tanksand connectionsconstitut-' ing a material portion of the longitudinal strength of thevessel and the whole ena: blin the architect to employ a less total weigheretofore "customary in tank vessels, substantially as described.

" 8. In a ship the combination of a double bottom having 'a perforatedtop plating; a plurality of ,overlapping tanks circular in cross sectionopen'at their bottoms and overlying saidperforated the walls. of the onetank being omitted to accommodate a portion of the walls of an adjacenttank; rigid connections between said tanks at said omitted, portions;rigid connections between the bottom edges of said tanks and theperforated bottom'str'ucture of the vessel; rigld connections betweenthe top portions of said tanks and the top and dec t of metal in thesh1p than has been plating, a portion of structure of the vessel; andrigid connections between the sides of said tanks and the sides of saidvessel, said tanks and connecbottom having perforations in the topplating thereof; a plurality of overlapping 4 tanksfcircular in crosssection open at their ing said perforations, a

portion oftthe wa lsof the one tank being portion of the I d betweensaid tanks at said omitted'portions; 7

connections between the bottom edges of said tanks and thebottomstructure of the" vessel; rlgid connections between the top portionsofsaid tanks and the top structure'- of the vessel; rigid connectionsbetween the sides of mid and-the sides of said ves-' decks thecombmationof a plurality of in- Sci; and means for preventing'liqnid contained inone tank from flowing throu h said perforations and double bottom to t einterior of an adjacent tank; said tanks and connections constituting amaterial portion of the longitudinal strength of the vessel and therebyenabling the architect to employ a less total weight of metal in theship than has been heretofore eustomar in the usual tank vessel,substantiall as escribed.

10. In a ship provi edwith cut away tersecting cylindrical tanks fittedto said decks; connections between said tanks attheir overlappingportions; "adjacent tanks provided with a common end wall following thecylindrical contourof said tanks; connections between said tanks andsaid cut a away decks; and additional connections comprisin transversepartial bulk-heads between sai tanks and the sides of the ship;

said tanks and connections constituting a material portion of thelongitudinal stiffness of the vessel and thereby enabling the architractto employ a less total weight of-metal in the construction than hasbeenheretofore customar in converting a vessel into a. tanker o the samekind and. class, substantially as described.

11. In a shi the combination of a plurality of longitu inally disposedtanks extend-. ing on each side of the keel,'located in contact witheach other and having a cdmmon transverse wall of a cylindrical contourbe tween adjacent tanks; fasteningand stifining eonnections between thecontacting walls of said tanks; and additional fastening and stiffeningconnections between said tanks and the hull of the vessel, whereby saidtanks constitute a portion of the longitudinal stiffening of the vessel,substantially as described. 1 r

In testimony. whereof we afiix our signatures, in presence of twowitnesses.

JOSEPH WILLIAM ISHERWOOD.

JOHN WILLIAM STEWART- I Witnesses:

H. TENNANT, 'HARRY C. POJLLON.

